The present invention relates to a semiconductor device and a method of manufacturing the semiconductor device.
A semiconductor device has been miniaturized in recent years. As miniaturization has proceeded, the width of metal wiring lines in the device has narrowed, and, therefore, an aluminum comprising copper of about 0.5% by weight is generally used to prevent disconnection of a wire, or a hillock, in an aluminum wiring line due to migration.
However, in the case of the aluminum wiring line containing copper, there is a case where copper atoms are precipitated. The location of precipitation is around a grain boundary or an interface between an adjacent conductor layer and a main wiring layer. Especially, when a precipitate become large around the interface, there is a case where the precipitates remain there since the precipitate is not etched. In the case where a wiring interval (space between wirings) is narrow, it is a cause of short circuit failure between adjacent wiring lines.
Since there is a tendency that not only a width of the wiring line but also an interval between wiring lines narrow, the problem of short circuit failure can be serious. Then, for example, Japanese Patent Laid Open No. 186175/1996 discloses a method in which after forming an aluminum film and dissolving copper into the aluminum at high temperature, rapid cooling is carried out to prevent copper precipitates at the cooling.